Tractor attachment for automobiles



May 1&5,4 1,923.

\` '.l. R. sTEPHNsoN ETvAl.

TRACTOR ATTACHMENT FOR AUTOMOBILES Filed Dec. l2

5 Sheets-Sheet l D17-1E. me/www.

May 15, 1923. 1,454,9M

J. R. STEPHENSON ET Al TRACTOR ATTACHMENT FOR AUTOMOBILES Filed Dc. 1g,1919 5 sheetsfsheet 2 T.FtEpI-lEr-lmn- May 15, 1923.

J. R. STEPHENSON ET AL TRACTOR ATTACHMENT FOR AUTOMOBILES Filed Dec. 121919 l 5 Sheets-Sheet 5 6 B o D 0 0 Sme/whom May 15, 1923. l,454,9ll

J. R. sTEPHENsoN ET AL TRACTOR ATTACHMENT FOR AUTOMOBILES Filed DeoflZ1919 5 Sheets-Sheet 4 May l5, 1923. 1,454,911l

.'l. R. STEPHENSON ET AL TRACTOR ATTACHMENT FOR AUTOMOBILES Filed Deo.12 1919 5 Sheets-Sheet 5 A L ,f 1E' -la .15. ECE .En

Patented May l5, 1923.

vuiariifza STAT-Es Linen PATENT OFFICE.

JOHN YR. s'TnPinNsoN AND OLIVER, o. ARMSTRONG, or Los ANGELES.CALIFORNIA.

TRACTOR ATTCI'VIMNT FOR AUTOMOBILES.

Application filed December 12, 1919. Serial No. 344,426.

To all ywhom t may. concern.'

Be it known that we, JOHN R. STEPHEN .con and OLivicR C. ARMSTRONG,citizens ot the United States, residing at Los Angeles, in the count-yot Los Angeles and State ot California, have invented certain new anduseful Improvements in ITractor Attachments tor Automobiles, oft' whichthe following is a specilication.

This invention relates to tractor attach.- ments for automobiles, andthe primary object of the invention is to provide an improved means `forquickly and readily converting an ordinary automobile into a tractorwithout removing any parts thereof.

Another object ot' the invention is torpro-4 vide an improved tractorattachment for automobiles of any size or type embodying aii improvedmeans for connecting the same with the automobile, so as to eliminatethc necessity of employing a jack or other separa-te lifting means. f

A further object ot the inventionk is to provide a tractor attachmentfor autoincbiles embodying a novel type of gripping drum for engagingthe tires Otan automobile, so that the motive power Afor the tractorattachment may be taken directly from the drive wheels of the vehicle.

A still further object of the invention'is the provision of aI tractorattachment with the aching means associated therewith so as to permit aportion of the tractor frame to be lowered for receiving the automobileand means for raising the said portion, so as to move the drive wheelsof the motor vehicle out ot engagement with the ground.

A still further object of the invention is the provision ot improvedgripping drums for grasping the tires of the rear drive wheels of amotor .vehicle,`whicli are so constructed as to permit the saine to bebrought into or4 out of engagement with the tires to facilitate .thepositioningot the motor vehicle on the tractor.

A still further object of the invention is the provision of means forswinging the sections ot the gripping drums into Aengagement with theperiphery ot the tires of theA rear drive wheels and means forreleasably locking said sections in position.

A still further object of .the invention. is

to provide an improved tractor attachment ol' the above character which.is durable and efficient in use, one that is simple and easy tomanufacture, and one which` canbe placed upon the market at a`reasonable cost.

Other objects of the invention will Aappear inthe following detaileddescriptio-n taken in connection with the accompanying draw-r ingsforming a partY of thisispeci cation,v and in which drawings: y-

Figure 1 is a perspective view of an automobile having the .improvedtractor attachment associated therewith.

Figure 2 is a side elevation of the iinproved tractor attachment'.y l

Figure 3 is a top plan view ot the tractor` attachment showing parts ofthe same in section so as to disclose the interior` portions thereof. l

Figure 4 is a. longitudinal sectioiiftalnv on the line i-4 of Figure 3,showing one ot the tractor members in elevation.` y

Figure 5 is a detail front elevation of one of the tread members showinga part of the saine in section. i i v v c Figure 6 is a side elevationof one of thev gripping drums showing one ot the 4sections in openposition, another in partially open position, and the remaining sectionin itsv permanent position. i Figure 7 isa side elevation of one of thein section.

Figure 8 is a detail section'taken on the showing the `sections s{ripping drums showing parts of the same line 8 8 of Figure r in lockedposition. n y

liigiire 9 is a large detail view ofi one of the lock members for the`sections of the gripping drum. v

Figure 10 is a large detail section through the gripping drum showingone of the sections in partly opened position.

Figure 11 is a large detail side elevation ot one of the bull tractionwheels. I V Figure 12 is an end elevation of thesanie. Figure 13 is adetail section on the line 153-13 -ot Figure 11 showing the clutchmechanism in dotted lines." Y i Figure 14 is a detail side. elevation ofthe clutch mechanism. y l A.

Figure 15 is a transverse elevationof` the same. i y j Figure 16 is adetail transverse section on the line 1'6-16 of Figure l5..

Figure 17 is a transverse section through one of the envelope platestaken on the line 17-17 of Figure 18.

liigure y18 is a side elevation of one of the envelope plates.

Figure 19 is an elevation of one of the drive sprocket wheels, and

Figure 2O is a section on the line 20-2O of Figure 19.

Referring to the drawings, in detail,

wherein similar reference characters desig-J nate corresponding parts,throughout the several views, the letter A indicates an automobilehaving the improved tractor' attachment B connected therewith. Theautomobile A may be of any desired make, style or size, and includes thebody 25, the front wheels 24, and the rear drive wheels 2T having theusual pneumatic tires 23 connected therewith with which the tractorattachment B is adapted to engage.

The tractor attachment B includes a pair of grip drums C mounted on arotatable shaft D carried by the elevating frame E having a raising andlowering means or jack. rlhe elevating frame E is carried foroscillatory movement on the rear axle F havingl associated therewith thepair of spaced casings or housings G carrying the drive or treadsections H, which are operatively connected by drivingmechanism l withthe grip drums C and have associated therewith the clutch mechanism Jfor throwing the drive or traction members H into or out of operation.The elevating frames E carry for movement therewith the gripping drums Candv the semi-housings K which partially close the lower surface of thegripping drums C The gripping drums C are constructed identical with oneanother and one is adapted to engage one rear drive wheel while theother is adapted to engage the other rear drive wheel of the automobileA and each` includes the disc or plate 29, which is keyed or otherwiserigidly secured to the inner terminal of the shaft D. The disc or plate29 has an inwardly extending peri plieral flange 30 forming a segment ofa circle and a pair of movable sections 31 and 32 which form inconnection with the flange 30 an annular body or drum for engaging theperiphery of the ti es 23 of the rear wheels 27 of the automobile.

The sections 31 and 32 each include right angular walls 33 and 34 and itwill be seen that the walls 33 lie in substantially parallel relationwith the disc 29 and engage the outer face of the same when the sectionsare moved in their closed or operative position'.

The outer edge of the disc 29 has the portion thereof lying between theedges of the stationary flange 30 provided with teeth 35, which areadapted to engage the teeth 36 formed on the outer edge of segmentalplates 37 secured to the inner faces of the walls 33 'of the sections 31and 32 at the outer edge thereof, se that when the sections are movedinto locked position, movement circumferentially around the disc 29 bythe sections 31 and 32 will be eliminated. lip 38 is carried by thesegmental plates 37 and extends below the lower edge of the same so asto eliminate the lateral movement of the sections in relation to thedisc 29 when the sections are in their locked positions.

lThe inner faces of the walls 34 of the sections 31 and 32 and theflange 3() are provided with equi-distantly spaced gripping fingers 39having flexible friction pads 4U secured to their outer faces forengaging the periphery of a tire so as to firmly grip the same. Thefriction pads 40 may be made of any suitable material such as rubber or`the like. `The disc 29 is provided with a segmental reinforced extension41 formed on .its outer face extending from the central aXis of the discto the outer edge thereof, and the same extends from one end of theflange 30 to the other, and the sections 31 and are adapted to extendflush with the same when the sections are in their closed positions. Apair of parallel spaced toggle clamps 57 are provided for each of thesections 31 and 32 and each of the toggle clamps include arms 42 and 43,which have their outer terminals secured to the inner edge of the walls33 of the sections 31 and 32 and the disc 29 by pivot pins 44 and 45.The pivotpin 45 is positioned on the disc 29, a

.proper distance from the periphery thereof and just within the line ofjuncture of the walls 33 and the disc 29 when the segments 31 and 32 arein closed position.

The inner terminals of the arms 42 and 43 are pivotally connectedtogether by means of the pivot pin 46 and the arm 43 is provided at itslower end with extensions forming a retaining ear 47, which is adaptedto be engaged by rotatable locking member 43 mounted on a pin 50threaded or otherwise secured to the outer face of the disc. The lockingmembers 43 include an annular body having an annular extending flange 5lformed on the outer edge thereof behind which the ear 47 is adapted toengage.A portion of the flange 51 is notched as at 52 so as to receivethe ear 47 during the final positioning of the sections 31 and 32. Afterthe sections are in their closed positions, the locking members 43 areturned so as to move the notch out of the path of the ear 47. The toggleclamps permit the sections to be moved inwardly over a tire and thendownwardly into tight engagement therewith.

The shafts l) which carry the gripping drums C are each of the stub typeand are mounted in suitable bearings 49 secured to the upper surface ofthe elevating frame E at the outer ends thereof.

The elevating frames ll include pairs of A retaining spaced parallelbeams 53 and 54 respectively,A

. beams 53 and 54 are provided with right angularly depending'extensions 58, the inner surfaces of which are formed smooth to providea sliding bearing surface against theplates 2l attached to envelopeplates 59, f

thereby allowing vertical action and at t-he same time preventinglateral motion between the elevator frames E and the tread member'H,thereby retaining the elevator frames and the tread member H in properalignment relative to each other.

Positioned intermediate each pair of the elevating beams 53 and 54 arethe rectangular spaced enveloping plates 59 which form the housing Gr,for the track or tread mechanism H. The rear termina-ls of the platesare provided withrelatively large openings 60 through which the rearshaft F extends and these openings are surrounded by an annularreinforcing bearing flange 6l, the purpose of which will be hereinaftermore fully described. The forward ends ot' the enveloping plates 59 areprovided Vwith registering openings 62, which support the forward shafts63 which extend transversely across the tractor members from the outsideenveloping` plates to the inside enveloping plates of each member, towhich they are firmly attached by `keying or other method. The plates 59gradually increase in width toward their rear ends so as to conform tothe inclination of the upper run of the drive chains H.

The plates 59 are held in their spaced relation byL suitable retainingbolts and sleeves, as may be desired.

The track or tread mechanism H includes the relatively large bullsprocket wheel 65, which is rotatably mounted on the rear axle F forindependent movement and is arranged adjacent the rear end of thecasing, intermediate the plates 59. The side faces of the largebullwheel 65 have annular grooves 66. which are adapted to receive theannular enlargements 6l formed on the inner faces of the plates 59 andthese annular enlargements form supplemental bearings on the bull wheel.The peripheries of the bull wheels adjacent the outer edges thereof areprovided with vguard flanges 67 which hold the 'track tread fromslipping laterally thereof.. A plurality of equi-distantly spaced teeth68 are arranged on the peripheries of the bull wheels intermediate theside flanges thereof and form means for engaging the links of the tre-advchains 69. The tread chains 69 may be ofthe ordinary or any preferredtype used in caterpillar tractors and have spaced cleats or spurs 70..

secured to the outer surface thereof so that thev same may attain a firmgrip on the ground. The shafts 63 which are carried by the forward endsof the `spaced plates rotatably `carry the relatively small wheels 7landthe tread chain 69 is trained around y the same. The small wheels 71,carry a face v and guide Hanges similar to that ofthe 'bull wheels 65,but gear teeth are not provided thereon. These wheels 71,' serve only.as

idlers in the drive mechanism. ,'lfhershaft F Ahas also mounted thereon,for independent rotation, the drive sprocket wheels 72, which arearranged on the shaft between the outer enveloping plates 59 and theinner side of the elevating beam E. The shafts D which carry the drums Chave rigidly secured to their outer ends relatively small sprocketwheels 74 and a. drive sprocket chain 75 is trained `around the wheels72 and 74.I

A clutch mechanism J isv provided for formed in the bull wheel, and whenthe ring T6-is pushed inwardly the arms 77 willride v i f throughtheopenings 78 and Ainto the sockets 80, which will effectively lock thedrive sprocket wheel and the bull wheel 65 together, thus permitting theoperation of the said treadfchain. The ring 76is loosely mounted forrotary movement on a` Vcarrier ring 8l which allows divergent movementbetween it and the carrier ring when the device is swinging on the pin87 in operating the clutch. ,'llhe ring 76 has its outer -face recessedat diametrically spaced points for the reception of the links 82, whichare rotatably mounted on' pins 83.

The links` 82 carry outwardly extending lingers 84,

which are received in an annular groove 85 formed in the inner face ofthe ring 76.

=Thus it will be seen that the ring( 76 is adapted for rotary I'novementaround the carrier 'ring 8l and 1s held against lateral movement by thefingers 84.

spaced ears86, which receive the pivot pin 87,` by means of which theycarrier ring 81 is pivotally mounted uponone of the plates 59. Theupperend of the carrier ring diametrically opposite the ears 86 is provided lThe lowerend of the carrier ring 81 is provided with nected by anarcuate'plate 97.

with an operating handle 88, by means ot which the ring' 81 is adaptedto be swung' on said pivot. 1t can be seen by moving the operatinghandle 88 inwardly or outwardly, the lingers 7'? will be brought into orout ot engagement with the sockets 80. The 77T are adapted to be lockedin their adjusted positions by means ot a don; 89 and segmental raclr90. The segmental raclr90 entendsthrougrh opening 91 in the handle 88and has its inner end secured to the enveloping plate 59.

The envelope plates are furtherxheld in spaced parallel relation bymeans ot shafts 92 arranged at equi-distantly spaced points in ahorizontal plane adjacent the lower ends or" the plates and haverotatably mounted thereon the rollers 93 which are adapted to engage the'upper tace ol' the lower run oi' the drive or tread chains 69, so thatthe rhains may eliiectively grip the ground at the entire lower runofthe same. The slack in the upper run oi" the said chains 09 issupported by a pair et spaced rollers 9a mounted on the sha-ils mountedbetween the plates. The rollers 9/1 rotatably engage the low -face otthe upper run ol" the said chain.

Suliplemental casings l are provided for the grip drums t), and the samepartially embrace the lower ends of the same. Each olf the supplementalcasinos or semi-housings l includes a pair et spaced plates 96 whichhave their lower and r ends conllhe outer plates 96 ot the semi-housings`are firmly attached to the insideI elevator beams which have reduceddepending' extensions 0% which form a seat to receive said plates. Tierear ends. et the plates are also rigidly secured to transverse bracebeam 98, which is rigidly connected to the inner beams for securing` theinner beams together. The ber .is lil are rigidly bound together, inpairs near their forward teriniirals.l by the bind y plates 11S, vwhichare rigidly atlachen to their upper suriaaes and which bridge or spanthe tread mechanism. allowing' it to ride 'Vree between them. lt is tobe understood that any other bracing' means may be provided itnecessary.. T he :forward ends ot the semi-housings K are provided withinclined noses 99 which have the upper faces thereof serrated orroughened and form inclined runways for facilitating` the positioning'of the wheels, or an automobile in the Agrip drums C.

The forward terminals ot the casing/js rotatably carry the transverselyextending shaft 10th the outer ends ot which have keyed thereto thedrums or windlasses 101, which torni a portion or" the means forraising' andlowerinp; tie elevating beams and the grip drums C. Thesedrums or rwindlasses 101 have anchored thereto the lower terminals of apair ot spaced chains 102 which have their upper ends anchored to theupper terminals et' hood sections 103 which partially enclose theforward ends oli the envelopingl plates 59. @ne of' they drums 101 isformed relatively longer lthan the other and is provided with openings10st ""or the reception ot' an operating' lever 105, so that the drumsmay be readilykr rotated when it is desired to raise and lower theelevating; beams.

The drums 102 are provided with locks 100 'for holding` the saine inadjusted positions and these locks include the dogs 107 rigidly mountedon the outer terminals ol the shatt 10S, which is rotatably carried bythe terminals of the semi-housings. The doa's 107 are adapted to engagethe ratcaet wheels 109 rigidly secured to the shaft 100. Thus it will beseen that when the dogs 107 vengage the ratchet wheels 109 movement votthe drums is prevented.

fin operating; means 110 is provided for forming; au etlicient means torreleasing the dors and includes the crank arm 111, keyed to thtransverse shaft 1127 which is rotatably supported by the enveloping'plate. rllhe outer terminal ot thesha'tt 112 is eX- tended beyond theouter face ot"v one ot the enveloping' plates and has keyed thereto theoperating lever 113 carrying the pawl 114i which is adapted to engageteeth o' the arcuate raclr bar 115 secured to the outer tace o'f theenveloping plate. The upper end ot the 'crank arm 111 has pivotallysecured thereto the connecting rod 116 which extends parallel to theplate 59 and into the opening in the arm 117 secured to the shaft 108.The rod 110 provided with an annular flange 119 so as to engage in theinner iiacelof the arm 117. so that when the rod 116 is pushed'forwardly by the lever 113, the shaft 108 will be rocked so as to movethe dogs out ot engagement with they ratchet wheels 109. The dogs 10Tare held in engagement with the ,atchet wheels by means ot' an expansionspring' 120 which is coiled around the rod 110 and the terminals o1 thespring; 120 engage the outer 'tace ol the arm 11"? and inner tace oli'the loclr nut 121.

To prevent the treador caterpillar chain from becomingv clogged with mudor the like, suitable scraper plates 122 are provided for engaging thetreads at the rear end thereof and the scraper 'plates are pivotallymounted intermediate their ends on pins 123 carried by the rearwardextending ears 124i formed on the envelopinga plates 59.

ln operation of the improved device, the elevating trames E carrying thegrip drums (l are lowered, when it is desired to placethe attachment inengagement with a motor vehicle by releasing` the dogs 107 from theratchet wheels 109. and by inserting the operating lever 105 into thesocket 10a formed lll) vwrench orthe like.

in the drums 101 for the reception of the same. The drums 101 arerotated sufiiciently to permit the forward ends of the inclined noses 99comingfinto engagement with the ground. The sections 31 and 32 of thegrip drums are then moved outwardly into an inoperative position overthe elevating beams by operating the locks 48 so as to position thenotches '52 in alignment with the ears-17 formed on the toggle clamps57. To facilitate the lrotating of the locks 48, the same are providedwith openings 125 for reception of a tool such as a spanner Tofacilitate the throwing bac-k of the sections 31 and 32, the same arealso provided with tool receivingsockcts 126. After the sections 31` and32 have been `thrown out of alignment with the stationary sections andover the elevating beams, the motor vehicle is backed up the runway andinto the stationary section which forms a cradle for the reception ofthe saine. l i

With the automobilein position in the stationary section, the movablesections 31 and 82 of the grip'drums are moved into place over thetreads of the tires of the rear wheels and between it andl thefender.The

toggle clamps 57 are forced downward and r inward thereby gripping ythetires firmly and preventingv movement vof the gripping drumscircumferentially on the tires. The

.flanged ,keepers or locks 48 are then turned so as to position the ears47 behind the vflanges thereof and prevent displacement of the clamps.The grip drums Carethen elevated to the desired -height according to theground over which the tractor `is intended to be moved by moving thelever 105 to rotate the drums or wiiidlasses 101.

The automobile is now ready for use as a'tractor and is operated in theusualmannel'.

is thrown outl of gear with the tread mem-l bers and the grip drums Carewrevolved in'- dependently, by hand, to a proper point of exit. Thetool insert holes 126 facilitate this rotation. i

It willbe readily understood, that in operation, when turning or drivingin curved lines, the drive wheels of the automobile revolve inequally,so that at a time, when it becomes desirable to disconnect theautomobile from the tractorv attachment, the grip drums may be in anyposition and for this reason, the clutch mechanism J is specificallyprovided.

After the grip drums C are revolved to the proper-point for e-Xit, theclutchvmechanism J is locked with the tread members and the grip drumsections 3'1 and 82 are released and thrown out of alignment aslieretofore described. The automobile is then i driven out of theattachment. f,

`The rear axle is provided with a 4suitable draw bar so that farmimplements may be attached thereto. If so desired the draw bar may berigidly attached to the elevating means orA enveloping plates 59.

The supplemental frames Khave secured between the plates 96 rollers 127which are arranged in any are of 'acircle concentric with-the gripdrums@ andare adapted to engage the periphery of the drums for form- 'ling lan additional support for the same. From the foregoing descriptionit can be seen that'a portable tractor. attachment is provided forautomobiles of exceedingly ,-731

simple and durable construction, whichwill entirely obviate thenecessity ofemploying jacksor other auxiliary tools for lifting theautomobile in position'.A i In practice, we have found that the form ofourinvention illustrated inthe accompanying drawings and referred to theabove description'as the preferred embodiment, is

the mos't eiiicient and practical, yet realizing i that the conditionsconcurrent with the adoption` of our device will necessarily vary, wedesire to emphasizethe fact that various `modifications, in details of,construct-ion,

proportion and arrangement of parts may Vbe resorted to when required,without sacrificing `any of theadvantages of our invention as set forth.

'What we claim as new is:

1. A tractor attachment for' the rear end of automobiles comprisingground 'l engaging elements, 'rotatable grip l, drums varranged tosupport the` drive wheels of .the

automobile, said grip drums constituting the o sole means of connectionbetween the attachment and the automobile, means for raising y'andlowering the drums and means operatively connecting the drums with theground engaging elements. y f

2. A tractor attachment for the rear end of automobiles comprisingground engaging f elements, rotatable grip drums arranged to support the,drivel wheels of theautomobile,`said grip drumsconstituting the soleVmeans of connection between the attachment and the automobile,- meansfor raising and.

lowering the drums, means forholding kthe 1 drums in raised position,and means for operatively connecting the drums with the "iA groundengaging elements.v

3. A tractor attachment for the rear end ot automobiles comprisingl'ground engaging elements` rotatable grip drums arranged to support thedrive wheels ot the automobile, said grip drums constituting the solemeans oit connection between the attachment and the automobiles, meansfor raising` and lowering); the drums, releasable means for holding thedrums in an adjusted position, and means '.or ope *atively connecting`the drums with the groundv en ,'ng elements.

4l. A tractor attacinnent for automobiles comprisir a trame, elevatingbeams pivotally carried by the trame, automobile wheel grip meanscarried by the beams,I drums tor raising and lowering' the elevatingbeams, and releasable means ror locking the raising and lowering drumsagainst accidental rotation.

5., A tractor attachment for automobiles comprising a trame, an axlecarried by the rear end oil' the frame, axles carried by the forward endof thc frame, bull gear wheels mounted on the rear axle, guide wheelscarried by the :front axles, tread chains trained around said bull gearwheels and said guide 'wheels elevating beams mounted on the ends of therear axle, automobile drive wheel engaging means carried by theelevating beams, means 'for raising and lowering the beams, and meansfor ogeratively connecting the drive wheel engaging means with the bullgear wheels.

6. ln a tractor attachment for automobiles, a grip drum arranged totrictionally engage the drive wheels ot an automobile including astationary tire engaging section and laterally moving swinging tireengaging sections adapted to be swung into and out ot tire engagingposition.

7. in tractor attachment ttor automobiles, a gripping drum arranged toengage the drive wheels ot an automobile and includine' a stationarycradle section and laterally :in outwardly movin swinqfj'iiigsectionsVfor locli ,he wheels in the cradle section.

8. in a tractor a tachment for automobiles, grip drum engaging the drivewheels ot' a motor'vehicle including a disc, a stationary segmentalsection carried by the disc, movable sections hingedly carried by thedisc and lool/ring means carried by the disc for engaging the movablesections to hole the same against displacement.

`9. ln a tractor' attachment 'for automobiles, a grip drum for engagingthe drive wheels of an automobile including` a disc, a stationarysegmental section carried by the disc, movable segmental sectionshingedly carried by the disc, and interlocking means carried by theouter edge of the disc and movable sections tor holding the sectionsagainst relative movement around said disc.

10. ln a tractor attachment for automobiles, a grip drum engaging thedrive wheels including a disc, a stationary segmental attachment carriedby the disc, movable segmental sections carried by the disc havingysingularly related walls, toggle clamps carried by the disc and movablesections, a lock for engaging the clamps to hold the same againstmovement when the movable sections are in their operative positions.

ll. ln a tractor attachment for automobiles, a iframe, an axle carriedby the rear end of the frame, axles carried by the forward end of thetrame, bull gear wheels carrier by the rear axle, guide wheels carriedby the front axles, tread chains trained around said bull gear and guidewheels, elevating beams mounted on the rear axle, grip drums carried bythe forward ends ot the elevating beams, means operatively connectingeach grip drum with a bullk wheel, a supplemental casing carried by theelevating beams and including the inclined runway arranged inalignment'with the grip drum, a shaft rotatably carried by thesupplemental casing, drums mounted on the last mentioned shaft, chainssecured tothe drums and to the frame, means for rotating the drums, andmeans for locking the drums against rotation. v

12. ln a tractor attachment for vmotor vehicles, a frame, a grip drumfor engaging one of the rear drive wheels ot a motor vehicle, the gripdrum including a stationary section and laterally movable'hingedsections, means rotatably connecting the grip drum with the frame, aninclined runway carried by the trame, means for raising and loweringsaid runway, the rigid section oi' the gripping drum being adapted formovement into alignment with the runway when a vehicle is beingconnected to or disconnected rom the 1 attachment.

13. ln a tractor attachment for motor vehicles, a trame, ground engagingmeans carried by the frame, a motor vehicle ground wheel engaging gripdrum carried by the trame for rotary movement including a stationarysection, and laterally swinging movable sections, means connecting thegrip drum with the ground engaging means, a hinged runway7 means forraising and lowering the runway, the stationary section of the grip drumbeing adapted to be moved into valignment with the runway, when a motorvehicle is being connected to or disconnected from the attachment.

JOHN R. STEPHENSON. OLIVER C. ARMSTRONG.v

